NUMERICAL SIMULATION OF CARDIAC ELECTROPHYSIOLOGY

心电生理数值模拟

• 批准号: 2881401
• 负责人: Bradley John Roth
• 金额: $ 5.85万
• 依托单位: OAKLAND UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-01 至 2001-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2881401
• 关键词: electroporation; electrostimulus; heart electrical activity; mathematical model; membrane potentials; microelectrodes; model design /development; myocardium; nerve threshold

DESCRIPTION (adapted from the applicant's abstract): The primary goal of this proposal is to better understand electrical stimulation. 1) The first specific aim is to calculate the strength-interval curve. The strength-interval curve plays an important role in determining the excitability of cardiac tissue. Preliminary studies suggest that the shape of the strength-interval curve is determined by a complex interaction between the spatially inhomogeneous transmembrane potential distribution and the nonlinear properties of the membrane ionic channels. A hypothesis is that more sophisticated models of cardiac tissue also lead to similar shaped strength-interval curves. Experiments show that the strength-interval curve changes with time after an electrode is implanted in the heart. A hypothesis is that tissue damage around the electrode causes the anodal strength-interval curve to shift to larger intervals with time. 2) The second specific aim is to clarify the mechanism of reentry induction. Preliminary studies predict that a modification of the tissue refractory period arising from the inhomogeneous transmembrane potential distribution around a stimulating electrode causes reentry, but that the reentrant wave front is not stable. A hypothesis is that a better model of cardiac tissue will predict a stable, reentrant pattern. 3) The third specific aim is to determine how electroporation will affect stimulation thresholds and reentry. During electrical stimulation from a unipolar electrode, the transmembrane potential can reach levels at which electroporation occurs. A hypothesis is that electroporation will change the cathodal threshold to a greater extent than the anodal threshold. 4) The fourth specific aim is to calculate the strength-interval curves for biphasic stimulation. A hypothesis is that biphasic stimulation will affect "break" stimulation to a greater extent than "make" stimulation. 5) The fifth specific aim is to determine the effect of inhomogeneities on unipolar stimulation of cardiac tissue. Computer simulations based on the bidomain model will be used to achieve these specific aims and test these hypotheses.

描述（改编自申请人的摘要）：主要目标 这个建议是为了更好地理解电刺激。 1）第一个 具体目标是计算强度-间隔曲线。 这 强度-间隔曲线在确定 心脏组织的兴奋性。 初步研究表明，形状 强度-间隔曲线的形状由复杂的相互作用决定 空间不均匀的跨膜电位分布和 膜离子通道的非线性特性。 一个假设是 更复杂的心脏组织模型也会导致形状相似 强度-间隔曲线。 实验表明，强度-间隔曲线 电极植入心脏后随时间变化。 一个 假设是电极周围的组织损伤导致阳极 强度-间隔曲线随着时间的推移转向更大的间隔。 2) 的 第二个具体目标是阐明再入诱导机制。 初步研究预测，组织难治性的改变 由于跨膜电位分布不均匀而产生的周期 刺激电极周围会导致折返，但折返波 前面不稳定。 一个假设是更好的心脏组织模型 将预测稳定的可重入模式。 3）第三个具体目标是 确定电穿孔将如何影响刺激阈值和 再入。 在单极电极的电刺激过程中， 跨膜电位可以达到发生电穿孔的水平。 一个 假设电穿孔会将阴极阈值改变为 比阳极阈值更大的范围。 4）第四个具体目标是 计算双相刺激的强度间隔曲线。 一个 假设双相刺激会影响“中断”刺激 比“制造”刺激的程度更大。 5）第五个具体目标是 确定不均匀性对心脏单极刺激的影响 组织。 基于双域模型的计算机模拟将用于 实现这些具体目标并检验这些假设。